Forgive me, but if you need to do this exact same series of steps for around 400 computers I feel you are doing it backward. Instead of having your local machine send a script to these machines, why not have the machines download the script from you?
Assuming you have OpenSSH server running on your local machine (or if you have a server anywhere that you feel can host the script) you could put a crontab on your 400 machines that looks like this:
Then enable a cron job to run the script for you as root once every hour/day/week. Just make sure that the remote machines
# wait for a random period of time no more than one hour
sleep_time=$(($RANDOM % 3600))
# save the previous script used
mv command_script command_script-backup
# download new script
scp your-hostname:scriscript_name command_script
# don't run it if the script is hasn't changed
cmp command_script command_script-backup && exit 1
chmod 755 command_script
1) Have the script installed
2) Have the proper crontab entry
3) Have permission to access your machine or the server where the new script will be.